/*
 * Copyright 2000-2012 JetBrains s.r.o.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.jediterm.terminal.util;

import org.jetbrains.annotations.NotNull;

public class Pair<A, B> {
    public final A first;
    public final B second;

    @NotNull
    public static <A, B> com.jediterm.terminal.util.Pair<A, B> create(A first, B second) {
        return new com.jediterm.terminal.util.Pair<A, B>(first, second);
    }

    public static <T> T getFirst(com.jediterm.terminal.util.Pair<T, ?> pair) {
        return pair != null ? pair.first : null;
    }

    public static <T> T getSecond(com.jediterm.terminal.util.Pair<?, T> pair) {
        return pair != null ? pair.second : null;
    }

    @SuppressWarnings("unchecked")
    private static final com.jediterm.terminal.util.Pair EMPTY = create(null, null);

    @SuppressWarnings("unchecked")
    public static <A, B> com.jediterm.terminal.util.Pair<A, B> empty() {
        return EMPTY;
    }

    public Pair(A first, B second) {
        this.first = first;
        this.second = second;
    }

    public final A getFirst() {
        return first;
    }

    public final B getSecond() {
        return second;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        com.jediterm.terminal.util.Pair pair = (com.jediterm.terminal.util.Pair) o;

        if (first != null ? !first.equals(pair.first) : pair.first != null) return false;
        if (second != null ? !second.equals(pair.second) : pair.second != null) return false;

        return true;
    }

    public int hashCode() {
        int result = first != null ? first.hashCode() : 0;
        result = 31 * result + (second != null ? second.hashCode() : 0);
        return result;
    }

    public String toString() {
        return "<" + first + "," + second + ">";
    }
}
